They do not like to play with the puck. They allow too many odd-man rushes. The quality of their lineup falls off after their first two lines. Entering Tuesday’s game, they had lost four of their last five games while allowing 23 goals. Tuesday marked the 13th time the Leafs have allowed 40 or more shots.

For all those flaws, Toronto beat the best team in the Atlantic Division at TD Garden, 4-3.

The Bruins are not playing bad hockey. They dominated the Leafs in the first period. They winged 15 pucks on goal. Thirteen other attempts either went wide of the net or hit bodies in front.

But unforced mistakes at untimely occasions led to four Toronto goals. Even against a down-and-out team like the Maple Leafs, a collection of errors will not lead to two-point results.

“You could see that our team as a whole, we weren’t in synch,” said coach Claude Julien. “From our breakouts, we rimmed a lot of pucks versus making clean passes. As a whole, we’ve got to clean up our game that way.”

The Bruins are 3-5-0 in their last eight games. Their slump coincides with the absence of Dennis Seidenberg, gone for the year. A string of little mistakes can pile up into a handful of losses, especially when your second-best defenseman is missing.

The Bruins lost the game in the second period. The Leafs busted a 2-2 tie at 7:09 when Jake Gardiner scored a power-play goal.

The Leafs worked well at spreading out Boston’s penalty kill. When the Bruins opened up their PK box, they left seams behind. The Leafs exploited them with rapid puck movement and smart shifts into soft spots. Gardiner took advantage with a snap shot from the right circle for the winning goal.

But the Bruins gave away the game in the first when they had it by its throat.

The Bruins dominated the puck. They won battles along the boards, which led to Brad Marchand’s opening goal at 3:38. They pushed the Toronto defense back with their speed. They didn’t allow the Leafs to get many sniffs on Tuukka Rask.

But the Leafs, if anything, are opportunistic. They have high-end skill at the top of their lineup. When a team like the Bruins is misfiring slightly in just about every area, good players turn those mistakes into goals.

Toronto started its rally when Tyler Bozak won an offensive-zone faceoff against Gregory Campbell. By winning it cleanly, Bozak forced the Bruins to scurry. Like most teams when they’re chasing the puck, the Bruins are not as good as when they have it in their control. Moments later, after Rask stopped a Carl Gunnarsson one-timer, Bozak drove to the net and popped in the tying rebound.

The Bruins pulled back ahead at 10:48 of the first. After scooping the puck off the end boards, Bergeron backhanded a shot between Jonathan Bernier’s glove and the post.

But the Bruins gave the Leafs another puff of life less than two minutes later. The trouble started when Carl Soderberg approached the end of his shift. He should have dumped the puck in and scurried off the ice. He didn’t.

“You take a penalty because you don’t dump it in when you’re trying to get a line change,” Julien said. “Those are all things that are self-inflicted. Until we clean up that part of our game, it’s going to be a struggle.”

Toronto’s skilled power-play unit made the Bruins play catch-up. The Leafs used the points well. When the Boston forwards tried to pressure the top, the Leafs distributed the puck quickly. Before Rask knew what was going on, James van Riemsdyk had sent a cross-ice dish across the crease to Bozak. By the time Rask dove to his right, the game-tying puck was in the net.

“You don’t play bad. You don’t play great,” said Rask (22 saves). “You get these deflections and plays to the back door where you have no chance. It’s frustrating. But we can’t feel sorry for ourselves. Same for me. I’ve just got to battle through it and hope for the better. We showed in San Jose that when we’re stingy, we help everybody out. Today was another example. When we make terrible mistakes, it ends up costing us big-time.”

The penalty kill was 3 for 5. That’s not good enough, especially when the power play shoots blanks on three occasions.

The Bruins had to adjust their units because of the absence of Dougie Hamilton (mild concussion), their point man on the No. 2 formation. Ryan Spooner was promoted to the first unit. Milan Lucic went to the front of the net.

Zdeno Chara, usually the net-front presence on the first unit, moved back to the point on the second. Loui Eriksson replaced Spooner on the half-wall. Bernier turned back all six shots he saw on the power play.

“The PK here has been really good for a long time. We’ll get it back there,” Jarome Iginla said. “We’re working on our power play. We’ve had some great stretches this year too. We believe we can get it back. We know both sides are costly and very important in these tight games.”

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